System and method for network reliability

Abstract

A method performed by a network controller for providing network reliability. The method includes employing an Interior Gateway Protocol (IGP) proxy configured to communicate controller information about the network controller to the one or more network elements using IGP (Link-State Advertisement (LSA) or Link State Protocol Data Unit (LSP)) with a Controllers TLV. The method uses the controller information for proper election of a primary controller in the event of a network failure.

What is claimed is: 
     
       1. A method performed by a network controller of a controller cluster configured to control a network, the controller cluster comprising a plurality of network controllers, the method comprising:
 communicating, using an Interior Gateway Protocol (IGP) proxy, controller information about the network controller to one or more network elements in the network using IGP; 
 establishing an IGP adjacency relationship between the IGP proxy of the network controller and the one or more network elements in the network; 
 advertising controller information about the network controller to the one or more network elements, wherein the controller information is included in a Controllers Type/Length/Value (TLV), and wherein the Controllers TLV includes a number of controllers field that indicates a number of controllers connected to the network controller; 
 detecting a communication failure within the controller cluster that splits in the controller cluster into a plurality of controller groups; 
 advertising updated controller information about the network controller to the one or more network elements, the updated controller information reflecting a change to the controller information in response to detecting the communication failure; and 
 determining that the network controller is part of an elected primary group of the plurality of controller groups; and 
 advertising second updated controller information about the network controller to the one or more network elements when the network controller is an intent primary controller of the elected primary group, the second updated controller information indicating that the network controller is a current active primary network controller of the network. 
 
     
     
       2. The method of  claim 1 , wherein the IGP adjacency relationship between the IGP proxy and one or more network elements in the network is established over a control channel. 
     
     
       3. The method of  claim 1 , wherein the Controllers TLV is included in one of an Open Shortest Path First Version 2 (OSPFv2) Router Informational (RI) Opaque Link-State Advertisement (LSA), OSPFv3 RI Opaque LSA, or an Intermediate System to Intermediate System (IS-IS) Link State Protocol Data Unit (LSP). 
     
     
       4. The method of  claim 1 , wherein the Controllers TLV includes a bit field and a position field, the bit field when set indicates that a position indicated in the position field is the position of a current active primary controller. 
     
     
       5. The method of  claim 1 , wherein the Controllers TLV includes an old position field that indicates a position of the network controller in the controller cluster prior to the controller cluster being split. 
     
     
       6. The method of  claim 1 , wherein the Controllers TLV includes a priority field that indicates a priority of the network controller to be elected as a primary network controller. 
     
     
       7. The method of  claim 1 , wherein the Controllers TLV includes a Controller Identifier (ID) field that includes controller IDs of all controllers in the controller cluster. 
     
     
       8. A network controller of a controller cluster, the controller cluster comprising a plurality of network controllers of a network, the network controller comprising:
 a memory storing instructions; and 
 one or more processors in communication with the memory, the one or more processors configured to execute the instructions to cause the network controller to:
 communicate, using an Interior Gateway Protocol (IGP) proxy, controller information about the network controller using IGP; 
 establish an IGP adjacency relationship between the IGP proxy of the network controller and one or more network elements in the network; 
 advertise controller information about the network controller to the one or more network elements, wherein the controller information is included in a Controllers Type/Length/Value (TLV), and wherein the Controllers TLV includes a number of controllers field that indicates a number of controllers connected to the network controller; 
 detect a communication failure within the controller cluster that splits in the controller cluster into a plurality of controller groups; 
 advertise updated controller information about the network controller to the one or more network elements, the updated controller information reflecting a change to the controller information in response to detecting the communication failure; and 
 determine that the network controller is part of an elected primary group of the plurality of controller groups; and 
 advertise second updated controller information about the network controller to the one or more network elements when the network controller is an intent primary controller of the elected primary group, the second updated controller information indicating that the network controller is a current active primary network controller of the network. 
 
 
     
     
       9. The network controller of  claim 8 , wherein the IGP adjacency relationship between the IGP proxy of the network controller and one or more network elements in the network is established over a control channel. 
     
     
       10. The network controller of  claim 8 , wherein the Controllers TLV is included in one of an Open Shortest Path First Version 2 (OSPFv2) Router Informational (RI) Opaque Link-State Advertisement (LSA), OSPFv3 RI Opaque LSA, or an Intermediate System to Intermediate System (IS-IS) Link State Protocol Data Unit (LSP). 
     
     
       11. The network controller of  claim 8 , wherein the Controllers TLV includes a bit field and a position field, the bit field when set indicates that a position indicated in the position field is the position of a current active primary controller. 
     
     
       12. The network controller of  claim 8 , wherein the Controllers TLV includes an old position field that indicates a position of the network controller in the controller cluster prior to the controller cluster being split. 
     
     
       13. The network controller of  claim 8 , wherein the Controllers TLV includes a priority field that indicates a priority of the network controller to be elected as a primary network controller. 
     
     
       14. The network controller of  claim 8 , wherein the Controllers TLV includes a Controller Identifier (ID) field that includes controller IDs of all controllers in the controller cluster. 
     
     
       15. A network controller comprising:
 a memory storing instructions; and 
 one or more processors in communication with the memory, the one or more processors configured to execute the instructions to cause the network controller to:
 configure the network controller as a secondary network controller in a controller cluster; 
 establish an Interior Gateway Protocol (IGP) adjacency relationship between an IGP proxy of the network controller and one or more network elements in the network; 
 advertise controller information about the network controller to the one or more network elements, wherein the controller information is included in a Controllers Type/Length/Value (TLV), and wherein the Controllers TLV includes a number of controllers field that indicates a number of controllers connected to the network controller; 
 detect a communication failure with a primary network controller in the controller cluster; 
 advertise updated controller information about the network controller to the one or more network elements, the updated controller information reflecting a change to the controller information in response to detecting the communication failure; 
 determine that the primary network controller has failed; and 
 advertise second updated controller information about the network controller to the one or more network elements when the primary network controller has failed, the second updated controller information promoting the network controller from the secondary network controller to the primary network controller in the controller cluster. 
 
 
     
     
       16. The network controller according to  claim 15 , wherein determining that the primary network controller has failed comprises using a link state database (LSDB) in the IGP proxy to determine whether the IGP proxy is advertising the controller information to the one or more network elements in the network.